The research objectives of this study are to examine the relative role of arterial baroreceptors in regulating renal function and renal blood flow during alterations in plasma volume. We also will study the possible influence these receptors have on the volumes of the body fluid compartments and the daily intake and output of fluids and electrolytes. The studies will be performed in control dogs and dogs with denervated arterial baroreceptors. BIBLIOGRAPHIC REFERENCES: Goetz, K.L., G.C. Bond, and D.D. Bloxham, Atrial receptors and renal function. Physiological Reviews 55:157, 1975. Bond, G.C., and K.L. Goetz. Effect of hemorrhage on plasma ADH levels in sinoaortic denervated dogs. Texas Rep. Biol. Med. (Abstract)